They would slow the blade speed down and also cause your mower to work harder to run them, burning more fuel.

They should not slow the blade speed down, unless your motor is not strong enough and bogs. But from experience trying to balance a blade like that would be impossible. Hell it would almost be impossible to check it for balance. Besides they look to be universal blades that never fit perfect and would be out of balance the instant you put them on. I plan on looking at them while at GIE but I doubt I would sell them to a customer.

I think the big problem with balancing a blade that has 4 blades is that you are not just balancing the blade like a normal 2 sided mower blade. You are not only adding 2 more edges that need to be balanced but with those additional edges comes a lot more ways the blade can be off balance due to the different combinations.

Try taking two regular 2 edged mower blades and lay them on top of each other on a blade balancer in the shape of an X.

Next try to sharpen the different edges where both the blades then like parallel with the ground and show they are fully balanced.

I bet it takes a lot more time.

Why doesn't someone here contact that company and see if they can get a few blades to try out and review the product on the forum.

I got them today but the tolerance on the center hole was too tight and it wouldn't fit the spindle. They are shipping me out a new center adapter overnight. Looks like these folks will bend over backwards to make things right. I will report how it turns out.

Well, I was promised the center hole adapters would be shipped overnight on last Thursday. I still haven't received them. I'm very disappointed at this time. I think I'm going to just ask for my money back if I don't get them today.